An IaaS (Infrastructure as a Service) that provides establishment of a predetermined system environment (for example, a WEB server system, a file server system, a DB system, and the like) as a service is known. A user can establish a system environment without performing establishment or the like of physical computers using IaaS via a terminal coupled to the Internet.
An IaaS business operator provides the IaaS by operating a computer system that includes a plurality of physical computers, a network apparatus, and a storage apparatus. The system environment is established on this computer system. A bare-metal method, a virtualization method, and an LPAR (Logical Partition) method are known as a method for establishing a system environment on the computer system.
The bare-metal method is a method of allocating all physical resources of physical devices (CPU (Central Processing Unit) and memory) included in a physical computer to one system environment.
The virtualization method is a method of virtualizing (establishing virtual devices) physical resources of physical devices included in a physical computer and allocating the physical resources to a plurality of system environments.
The LPAR method is a method of subdividing physical resources of physical devices included in a physical computer and allocating partial physical resources out of the subdivided physical resources to one system environment only among a plurality of system environments. PTL 1 discloses a technique of this LPAR method.